The only option I find in the PDM metamodel is the 'Check on Commit', which appears to be specific to SQLAnywhere.
Which DBMS are you referring to?
Regardless, you do not need a script. To change all occurrences, all you need to do is use the 'Model/References' object list and add the attribute to the list using the 'Customize Columns and Filter' button. Once saved, you will find the attribute listed as an attribute in the references in the list. Select all rows and then just change the setting of the attribute you want. The same attribute for all references will now be changed. Select the OK or Apply buttons to save the change.